Retinitis Pigmentosa Group Research Articles

Loss of Peripheral Retinal Vessels in Retinitis Pigmentosa.

Retinitis pigmentosa (RP) is the most common inherited retinal disease and a major cause of irreversible vision loss. The purpose of this study was to assess peripheral retinal vessels in RP. Cross-sectional study. Patients with RP and age-matched controls. Using ultra-wide field fundus images, the retina was divided into three zones: posterior, mid periphery, and far periphery. To evaluate vascularity of the retina, the vessels were counted at the border of posterior and mid peripheral zones (Z1/2) and the border of mid peripheral and far peripheral zones (Z2/3). Vessel counts at Z1/2 and Z2/3. 181 eyes of 107 RP patients and 130 eyes of 84 controls were included. In the RP group, the median vessel counts at Z1/2 and Z2/3 were 8 and 3, respectively. These were strikingly lower than the control group with the median vessels of 42 and 43.5 at Z1/2 (p<0.001) and Z2/3 (p<0.001), respectively. 22% of RP eyes were entirely avascular in the far periphery and 7% were avascular in the mid periphery and far periphery. Only 5% of RP eyes had more than 25 vessels at Z2/3. There were significantly fewer vessels in the temporal retina at both Z1/2 (p=0.01) and Z2/3 (p<0.001) in RP eyes. Furthermore, eyes with visual acuity of 20/200 or worse had significantly fewer vessels at Z1/2 (p<0.001) and Z2/3 (p<0.001). There were no significant differences in the number of vessels at Z1/2 and 2/3 between the right and left eyes of RP patients with both eyes included in the study. This study provides compelling evidence of substantial symmetrical peripheral retinal vascular loss in RP. This finding may aid in clinical diagnosis of the disease and have significant therapeutic implications.

Emotional State Evaluation of Retinitis Pigmentosa Patients with the Beck Depression Inventory.

To evaluate the incidence and severity of depression in patients with retinitis pigmentosa (RP). The Beck Depression Inventory (BDI) was administered to 74 patients with RP and 60 healthy controls. Biomicroscopic anterior segment and fundus examination, visual field, optical coherence tomography, and full-field electroretinography tests were performed in all cases. Variables were evaluated with bivariate, multiple linear, and ordinal logistic regression analyses. The RP group included 40 (54%) male and 34 (46%) female patients, while the control group included 23 (38%) male and 37 (62%) female subjects. The patient group had a mean age of 39.20±12.4 years, median best corrected visual acuity (BCVA) of 0.10 decimal (1.0 logarithm of the minimum angle of resolution [logMAR]; range, 1.3-0.7 logMAR), and median visual field mean deviation (MD) score of -28.00 decibels (dB) (range, -1.00 to -34.00 dB). The median BDI score was statistically significantly higher in the patient group (19 points) than in the control group (12 points) (p<0.001). Moderate to severe depression (BDI ≥20) was detected in 61% of patients, while this rate was 25% in healthy controls. BCVA and visual field MD values were identified as predictors of depression score and severity level. The patients' age and gender did not affect total depression score or severity. The prevalence and severity of depression were found to be higher in RP patients than in healthy controls. There was a significant relationship between the patient's functional vision tests and the frequency and severity of depression. Depression reduces the reliability of visual function tests and impairs patients' quality of life. Therefore, assessing mental health as well as functional tests is important in patients with RP.

Evaluation of Full-Field Stimulus Threshold Test Results in Retinitis Pigmentosa: Relationship with Full-Field Electroretinography, Multifocal Electroretinography, Optical Coherence Tomography, and Visual Field.

The full-field stimulus threshold (FST) test was developed to evaluate the efficacy and safety of treatments of hereditary retinal diseases. In this study we performed the FST test in patients with retinitis pigmentosa (RP) and compared the results with findings from other ophthalmological tests. The study included 51 intermediate and advanced RP patients and 21 normal subjects. All patients and controls underwent routine examination and ophthalmological tests including visual field, optical coherence tomography, full-field and multifocal electroretinography (mfERG), and FST tests. During FST testing, the perception thresholds of retina to the white, blue, and red FST were determined in decibels. The mean age of the patients and the controls were 35.2 and 33.5 years, respectively. For all RP patients, no response was obtained on full-field ERG. All subjects were able to perform reliable FST tests. The mean values of visual acuity and central macular thickness were significantly lower and visual field mean deviation values were significantly higher in the RP group than the controls. When we evaluated the mfERG findings, the mean P1 wave amplitudes in all rings were significantly lower and the mean peak times were significantly longer in RP patients than controls. In comparisons of FST test results, the mean values for white, blue, red and the difference between blue-red thresholds were significantly lower in the RP group than the control group. The FST test is a fast and a reliable exam which can be done in subjects with poor visual acuity and reduced visual field. The results of this study confirm that the FST test can measure retinal sensitivity in severely affected RP subjects with flat flash ERG.

Evaluation of Structural Retinal Layer Alterations in Retinitis Pigmentosa.

Objective: This study aimed to analyze retinal layers in the macular region using spectral-domain optical coherence tomography (SD-OCT). Additionally, we examined the retinal vascular plexus densities of the eyes using optical coherence tomography angiography (OCT-A), specifically in patients with retinitis pigmentosa (RP). Methods: In the study, 36 eyes from patients with retinitis pigmentosa (RP) and 36 eyes from healthy controls were included. Measurements involved assessing the thicknesses of each retinal layer at the central fovea, parafoveal, and perifovea using spectral domain optical coherence tomography (SD-OCT). Moreover, the study involved the evaluation of retinal capillary plexus densities (RCPD), encompassing deep capillary plexus density values, superficial capillary plexus, and radial peripapillary capillary plexus. This assessment was performed using optical coherence tomography angiography (OCT-A). Results: No statistically significant difference in retinal thickness was found in the central fovea between the two groups. The thicknesses of the INL, OPL, and PRL in the parafoveal regions as well as the RPE in the perifoveal regions increased in the RP group. Nonetheless, the ONL, IPL, GCL, and RNFL demonstrated reduced thickness in both the perifoveal and parafoveal areas. The OCT-A findings indicated that patients with RP exhibited lower values for all RCPD. Conclusion: The retinal layers and RCPD were significantly impacted at varying rates of RP. It is essential to acknowledge that this alteration may be significant in the context of the retinal findings in patients with RP. Abbreviations: SD-OCT = Spectral-domain optical coherence tomography, OCT-A = Optical coherence tomography angiography, RP = Retinitis pigmentosa, ETDRS = Early Treatment Diabetic Retinopathy Study, SD = standard deviation, TRT = Total Retinal Thickness, IRT = Inner Retinal Thickness, ORT = Outer Retinal Thickness, RNFL = Retinal Nerve Fiber Layer, GCL = Ganglion Cell Layer, IPL = Inner Plexiform Layer, INL = inner nuclear layer, OPL = Outer Plexiform Layer, ONL = Outer Nuclear Layer, PRL = Photoreceptor layer, RPE = Retinal Pigment Epithelium, µm = micrometer, PaFoSu = parafovea superior, PeFoSu = perifovea superior, PaFoNa = parafovea nasal, PeFoNa = perifovea nasal, PaFoTe = parafovea temporal, PeFoTe = perifovea temporal, PaFoIn = parafovea inferior, PeFoIn = perifovea inferior.

El espacio supracoroideo en pacientes afectados por retinosis pigmentaria

Background and objectiveThe suprachoroidal space (SCS) is a theoretical structure which can be demonstrated between the inner border of the sclera and the outer boundary of the choroid. SCS is being studied for its potential uses as a route for drug delivery and innovative surgical techniques for the treatment of many retinal diseases. Retinitis pigmentosa (RP) is a group of inherited eye disorders characterized by a gradual loss of photoreceptors, resulting in vision impairment, which typically presents as night blindness and progressive visual field loss. The purpose of the study is to define the morphology of outer choroidal margins by means of SS-OCT in RP. Material and methodThis is a retrospective observational study designed to evaluate the presence of SCS in RP. We performed swept source optical coherence tomography (SS-OCT) in a group of 55 patients affected by RP (26 males and 29 females, 110 eyes) with a mean age of 51.8±13.7 years. In the control group, we included 28 healthy subjects (6 males and 22 females, 56 eyes) with a mean age of 48.8±16.6 years. ResultsOCT scans allowed the outer choroidal margin and inner scleral margin to be delineated with certainty in all 110 eyes. In the RP group SCS was detected in 47 of 110 eyes (42.7%), in the control group SCS was detected in 11 eyes (19.6%).Subjects with SCS visible (RP group) had reduced retinal thickness (168.4μm) compared to those with not visible SCS (211.2μm, p=0.007). ConclusionsSS-OCT can be successfully applied to assess the presence of SCS in RP and the high rate of SCS found in the RP patients is encouraging when considering future innovative therapies.

Chromatic pupillometry isolation and evaluation of intrinsically photosensitive retinal ganglion cell-driven pupillary light response in patients with retinitis pigmentosa.

The pupil light response (PLR) is driven by rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs). We aimed to isolate ipRGC-driven pupil responses using chromatic pupillometry and to determine the effect of advanced retinitis pigmentosa (RP) on ipRGC function. A total of 100 eyes from 67 patients with advanced RP and 18 healthy controls (HCs) were included. Patients were divided into groups according to severity of visual impairment: no light perception (NLP, 9 eyes), light perception (LP, 19 eyes), faint form perception (FFP, 34 eyes), or form perception (FP, 38 eyes). Pupil responses to rod-weighted (487 nm, -1 log cd/m2, 1 s), cone-weighted (630 nm, 2 log cd/m2, 1 s), and ipRGC-weighted (487 nm, 2 log cd/m2, 1 s) stimuli were recorded. ipRGC function was evaluated by the postillumination pupil response (PIPR) and three metrics of pupil kinetics: maximal contraction velocity (MCV), contraction duration, and maximum dilation velocity (MDV). We found a slow, sustained PLR response to the ipRGC-weighted stimulus in most patients with NLP (8/9), but these patients had no detectable rod- or cone-driven PLR. The ipRGC-driven PLR had an MCV of 0.269 ± 0.150%/s and contraction duration of 2.562 ± 0.902 s, both of which were significantly lower than those of the rod and cone responses. The PIPRs of the RP groups did not decrease compared with those of the HCs group and were even enhanced in the LP group. At advanced stages, ipRGC responses gradually became the main component of the PLR. Chromatic pupillometry successfully isolated an ipRGC-driven PLR in patients with advanced RP. This PLR remained stable and gradually became the main driver of pupil contraction in more advanced cases of RP. Here, we present baseline data on ipRGC function; we expect these findings to contribute to evaluating and screening candidates for novel therapies.

Microvascular quantitative metrics in retinitis pigmentosa using optical coherence tomography angiography

AimsTo describe the changes in vessel density (VD) using optical coherence tomography angiography (OCTA) of the different sectors in the macular area between retinitis pigmentosa (RP) patients and controls. MethodsObservational case-control study. We initially included 22 patients with RP and 21 controls. We obtained 6 × 6 OCTA images of the macular area using Angio-OCT SS-DRI-Triton 1.22 (Topcon, Japan), together with visual acuity, biomicroscopy, visual field and optical coherence tomography examination. We compared the VD values in both groups for both superficial (SVP) and deep vascular plexus (DVP). Correlation between VD and macular thickness was also calculated. ResultsThe mean visual field index (VFI) in the RP group was 26.11% (±17.29). VD was significantly lower in the RP group compared with healthy controls in all sectors of the DVP (Superior 43.48 ± 3.79 vs 48.86 ± 2.62, P < .0001; Nasal 40,52 ± 4.30 vs 46,01 ± 3.23, P = .0002; Inferior 42.76 ± 5.26 vs 50.10 ± 3.36, P < .0001; Temporal 40.42 ± 4.46 vs 46.09 ± 2.91, P = .0001) and in all but nasal sector in the SVP (Superior 39.86 ± 4.46 vs 46.47 ± 2.61, P < .0001; Nasal 40.35 ± 4.56 vs 44.09 ± 2.87, P = .0067; Inferior 40.74 ± 4.61 vs 46.58 ± 3.26, P = .0002; Temporal 39.98 ± 5.07 vs 44.78 ± 3.28, P = .0024). Correlation between VD and macular thickness was positive and significant (RP: r = 0.59, P = .043; controls r = 0.51, P = .018). ConclusionsPatients with advanced forms of RP have less vessel density in the macular area than healthy subjects. These differences are present in all four quadrants in the DVP and three in the SVP.

Corneal characteristics in patients with retinitis pigmentosa

BackgroundTo evaluate corneal topography and specular microscopic findings in patients with retinitis pigmentosa. MethodsOne hundred and two eyes of 51 patients with retinitis pigmentosa and 60 eyes of 30 healty subjects were included in our study. A detailed ophthalmological examination involving best corrected visual acuity (BCVA) was performed. A rotating Scheimpflug imaging system, was used to evaluate all eyes for topographic and aberrometrics parameters. Specular microscopy measurements were also noted. ResultsThe retinitis pigmentosa group consisted of 51 patients (29 male and 22 female, mean age of 35.61±13.55 (18–65) years and the control group also consisted of 30 healty subjects (29 male and 22 female, mean age of 33.67±9.92 (20–58) years. There was no difference between the groups in terms of age (p = 0.624) and gender (p = 0.375). Spherical equivalents were higher in the RP group (p<0.001). Central keratoconus index (CKI) (p<0.001), Belin Ambrosio enhanced ectasia display total deviation value (BAD-D) (p = 0.003), index of surface variance (ISV) (p<0.001), index of vertical asymmetry (IVA) (p<0.001), Ambrosio related thickness (ART max) (p = 0.018), index of height asymmetry (IHA) (p = 0.009), index of height decentration (IHD) (p<0.001), maximum anterior elevation (p<0.001), front elevation in thin location (p = 0.05), progression index average (p = 0.015), root mean square (RMS) total (p = 0.010) and RMS-higher order aberration (RMS-HOA) (p<0.001) values were higher in RP group. There was a weak negative correlation between BCVA and ART max measurements (r=-0.256, p = 0.009) in RP group. We detected keratoconus-suspect in 6 eyes and clinically manifest keratoconus in one eye in the RP group. ConclusionsPatients with retinitis pigmentosa may have corneal morphological disorders that may affect vision. In our study, corneal topographic pathologies including keratoconus and possible keratoconus were detected in RP patients.

Estudio de densidad vascular en pacientes con retinitis pigmentosa por medio de angiografía por tomografía de coherencia óptica

AimsTo describe the changes in vessel density (VD) using optical coherence tomography angiography (OCTA) of the different sectors in the macular area between retinitis pigmentosa (RP) patients and controls. MethodsObservational case-control study. We initially included 22 patients with RP and 21 controls. We obtained 6x6 OCTA images of the macular area using Angio-OCT SS-DRI-Triton 1.22 (Topcon, Japan), together with visual acuity, biomicroscopy, visual field and optical coherence tomography examination. We compared the VD values in both groups for both superficial (SVP) and deep vascular plexus (DVP). Correlation between VD and macular thickness was also calculated. ResultsThe mean visual field index (VFI) in the RP group was 26.11% (±17.29). VD was significantly lower in the RP group compared with healthy controls in all sectors of the DVP (Superior 43.48±3.79 vs 48.86±2.62, P<.0001; Nasal 40,52±4.30 vs 46,01±3.23, P=.0002; Inferior 42.76±5.26 vs 50.10±3.36, P<.0001; Temporal 40.42±4.46 vs 46.09±2.91, P=.0001) and in all but nasal sector in the SVP (Superior 39.86±4.46 vs 46.47±2.61, P<.0001; Nasal 40.35±4.56 vs 44.09±2.87, P=.0067; Inferior 40.74±4.61 vs 46.58±3.26, P=.0002; Temporal 39.98±5.07 vs 44.78±3.28, P=.0024). Correlation between VD and macular thickness was positive and significant (RP: r=.59, P=.043; controls r=.51, P=.018). ConclusionsPatients with advanced forms of RP have less vessel density in the macular area than healthy subjects. These differences are present in all four quadrants in the DVP and three in the SVP.

Thicknesses of the retina and choroid in children with retinitis pigmentosa

PurposeTo compare the retinal thicknesses (RT) and choroidal thicknesses (CT) in retinitis pigmentosa (RP) children with those of healthy children using enhanced depth imaging (EDI) optical coherence tomography (OCT). The RT and CT in different genetic subgroups of autosomal dominant RP (ADRP) and X-linked inheritance RP (XLRP) were further studied to investigate the characteristics of retinal and choroidal changes in the early stages of RP.MethodA retrospective analysis was performed on a group of patients with RP who underwent EDI-OCT. Thirty-two children (64 eyes) with RP and 28 age- and refraction-matched healthy children (56 eyes) were included in the study. Seven of the 32 RP children (14 eyes) had X-linked inheritance RP, and 10 (20 eyes) had autosomal dominant inheritance RP. RT and CT were measured by optical coherence tomography and compared between the 32 children with RP and 28 controls and between 7 XLRP and 10 ADRP children.ResultAmong the 32 children with RP, there were 18 males and 14 females with an average age of 6.6 ± 2.4 years. The mean RT was smaller in the RP group than in the control group at all of the locations. The mean temporal CT was smaller in the RP group (243.76 ± 60.82 μm) than in the control group (275.23 ± 40.92 μm) (P = 0.001), while there was no significant thinning on the foveal or nasal side.The best-corrected visual acuity of the XLRP group (0.40 ± 0.19) was worse than that of the ADRP group (0.68 ± 0.21) (P = 0.001), but the disease duration was the same (P = 0.685). The mean foveal RT was smaller in the XLRP group (173.85 ± 22.87 μm) than in the ADRP group (192.20 ± 9.70 μm) (P = 0.003), while there was no significant thinning at the other locations we studied. The mean temporal CT was smaller in the XLRP group (211.21 ± 69.41 μm) than in the ADRP group (274.45 ± 57.91 μm) (P = 0.007); CT measurements in XLRP children showed a more severe reduction on the temporal side.ConclusionThe choroid in RP children was preferentially smaller on the temporal side of the macula, and retinal thinning was relatively extensive. Children with RP have strong clinical and genetic heterogeneity. The XLRP children demonstrated greater RT reduction at the fovea and greater CT reduction at the temporal side of the macula than the ADRP children. Our findings also provide evidence that the changes in thicknesses may be indicative of the greater severity of XLRP versus ADRP in the early stage.

Evidence for visual cortical plasticity in retinitis Pigmentosa

AbstractPurpose: Neural plasticity upon visual loss remains a very controversial phenomenon. We asked how the changes in peripheral visual input in adult Retinitis Pigmentosa patients would impact the stability versus plasticity of neuronal population receptive fields in early visual areas.Methods: A total of 37 participants were recruited. The Retinitis Pigmentosa group (RP) included 12 patients with RP. The full‐field Control group (FFCnt) included 13 healthy participants that performed the original protocol (as the RP group); and an artificial scotoma Control group (ASCnt) (n = 12). Population Receptive Field (pRF) fMRI paradigms were used at 3 Tesla. The maximum field of view was 23° × 30°. The stimuli used for pRF estimation consisted in conventional single, 45° counter‐clockwise rotating wedge and expanding ring stimuli with a high‐contrast (~100%) flickering (8 Hz) checkerboard pattern. To resolve chronic from acute adaptive effects we performed an artificial scotoma experiment, in an independent control group.Results: The general increase of pRF size on eccentricity was found in both Retinitis Pigmentosa and control individuals as expected. Interestingly, in RP, the regression slopes of pRF size and eccentricity in V1 and V2 seem to collapse in RP patients, in contrast with controls. Analysis of the regression lines adjusted to the mean pRF size along eccentricity in the calcarine sulcus of RP and matched ASCnt showed a significant difference between slopes (F(1,296) = 15.01, p &lt; 0.001), corresponding to a group difference in pRFs size in more peripheral locations, suggesting plasticity. Artificial scotoma pRF mapping showed no evidence for rapid adaptation.Conclusions: We found evidence for long term visual plasticity in adult Retinitis Pigmentosa patients as demonstrated by increased size of peripheral neuronal population receptive fields in early visual areas, which could be explained by rapid adaptation mechanism.

Vessel density and choroidal vascularity index in patients with Bietti crystalline dystrophy and retinitis pigmentosa

ObjectiveTo evaluate and compare the vessel density (VD) using swept-source optical coherence tomography angiography (OCT-A) and the choroidal vascularity index (CVI) using spectral-domain optical coherence tomography (SD-OCT) in patients with Bietti crystalline dystrophy (BCD) and retinitis pigmentosa (RP). Materials and methodsA cross-sectional retrospective study was conducted on 26 eyes of 13 BCD patients, 26 eyes of 13 RP patients, and 26 eyes of 13 age- and gender-matched healthy individuals. BCD patients were further staged as having early, intermediate, and advanced disease. VD was assessed in five quadrants of the macula (superior, temporal, inferior, nasal, and center) using a modified ETDRS technique with OCT-A. SD-OCT scans were binarized using Niblack's autolocal threshold, and CVI was determined as the ratio of the luminal area to the total choroidal area. ResultsA significant difference was found in VD in all quadrants of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) slabs among the three groups (p < 0.001). A statistically significant difference was noted in the mean VD of temporal and inferior quadrants of the SCP and between the BCD and RP groups (p = 0.005, p = 0.015, respectively). A statistically significant difference was observed in the mean VD of the temporal, inferior, and nasal quadrants between the BCD and RP groups on DCP slabs (p = 0.002, p = 0.003, p = 0.003, respectively). The mean central choroidal thickness was 214.65±87.10 μm in the BCD group, 351.69±67.94 μm in the RP group, and 320.92±59.26 μm in the control group (p < 0.001). We found that CVI was significantly higher in the control group than BCD group (p < 0.001), and it was significantly lower in the BCD group when compared to the RP group (p < 0.001).There was no difference in CVI between RP and control groups (p = 0.948). Furthermore, the CVI was significantly lower in the intermediate and advanced disease stages than the early disease stage in the subgroup analysis of BCD patients (p < 0.001, p < 0.001, respectively). ConclusionCVI is a novel investigative tool to monitor disease progression. The CVI value was lower in BCD and RP patients than in the healthy subjects, and lower CVI values seem to be related to the disease severity in BCD patients. VD was also significantly lower in BCD patients when compared to RP patients, and VD analysis may help clinicians better understand the disease pathophysiology.

Retinal organoids and microfluidic chip-based approaches to explore the retinitis pigmentosa with USH2A mutations.

Retinitis pigmentosa (RP) is a leading cause of vision impairment and blindness worldwide, with limited medical treatment options. USH2A mutations are one of the most common causes of non-syndromic RP. In this study, we developed retinal organoids (ROs) and retinal pigment epithelium (RPE) cells from induced pluripotent stem cells (iPSCs) of RP patient to establish a sustainable in vitro RP disease model. RT-qPCR, western blot, and immunofluorescent staining assessments showed that USH2A mutations induced apoptosis of iPSCs and ROs, and deficiency of the extracellular matrix (ECM) components. Transcriptomics and proteomics findings suggested that abnormal ECM-receptor interactions could result in apoptosis of ROs with USH2A mutations via the PI3K-Akt pathway. To optimize the culture conditions of ROs, we fabricated a microfluidic chip to co-culture the ROs with RPE cells. Our results showed that this perfusion system could efficiently improve the survival rate of ROs. Further, ECM components such as laminin and collagen IV of ROs in the RP group were upregulated compared with those maintained in static culture. These findings illustrate the potential of microfluidic chip combined with ROs technology in disease modelling for RP.

Progression Rate of Visual Function and Affecting Factors at Different Stages of Retinitis Pigmentosa.

We reviewed medical records of 121 patients/235 eyes of typical retinitis pigmentosa (RP) patients who could be followed up for at least 5 years with the aim of investigating the long-term course of visual function progression at each RP stage and appropriate assessment methods. Patients were classified into three groups: mild RP (baseline mean deviation (MD) ≥ −5), moderate RP (−25 < baseline MD < −5), and late RP (baseline MD ≤ −25). Linear mixed-effect models were used to follow MD, the average retinal sensitivity of the central four points of the Humphrey field analyzer 10-2 program (S4), and visual acuity (VA) with increasing time. The associations among factors (baseline MD group, sex, hereditary form) and the interaction between each factor and time were also investigated. The mean reduction of the MD, S4, and VA for all patients was -0.37 dB/year, -0.25 dB/year, and 0.018/year, respectively. The moderate RP group had a faster progression than other groups in MD (-0.43 dB/year, p < 0.05). The moderate (-0.31 dB/year, p = 0.01) and late RP groups (-0.25 dB/year, p < 0.01) had faster progression than the mild RP group in S4. The late RP group had faster progression in VA than the other groups (0.03/year, p < 0.05). Females had a slower progression of the S4 (-0.15 dB/year, p = 0.02) and VA (0.01/year, p < 0.001) than males. The autosomal dominant group had a slower progression than the sporadic group in MD (-0.22 dB/year, p = 0.02); the autosomal dominant and autosomal recessive groups had a slower VA decline than the sporadic group (0.01/year, p = 0.03; 0.01/year, p = 0.04). Because the progression rates of VA and visual field test differed as per the RP stage, S4 and VA can also be useful assessment methods depending on the stage. Inheritance form and sex may affect the progression rate.

Patients with Retinitis Pigmentosa May Have a Higher Risk of Developing Open-Angle Glaucoma.

Background Retinitis pigmentosa (RP) is the most common retinal hereditary dystrophy, which can lead to blindness if it progresses. Similarly, open-angle glaucoma (OAG) is a genetic disorder. The similarities in genetic variants and pathophysiology between RP and OAG have been reported. We sought to explore whether patients with RP have a significantly higher risk of OAG development. Methods We enrolled patients with RP into the RP group through Taiwan's National Health Insurance Research Database from 2001 to 2013; we included a comparison group of 1 : 4 age- and gender-matched individuals without RP. We performed a Cox regression analysis to estimate the crude and adjusted hazard ratios (HRs) for OAG. We adjusted the following confounders in the Cox regression model: age, gender, diabetes mellitus, hypertension, and chronic kidney disease. Results We enrolled 6,223 subjects with RP and 24,892 subjects for comparison. The mean age of the cohort was 49.0 ± 18.1 years. The RP group had significantly higher percentages of diabetes mellitus, hypertension, and hyperlipidaemia. The cumulative incidence of OAG in patients with RP was 1.57%; this was significantly higher than that in the comparison group (0.58%, p < 0.0001). On univariate Cox regression analysis, the hazard of OAG development was significantly greater in the RP group than in the comparison group with an unadjusted HR of 2.86 (95% confidence interval, 2.21–3.70). The increased risk persisted after adjusting for confounders (adjusted HR = 2.86; 95% CI, 2.21–3.70). Conclusions This nationwide population-based cohort study showed that people with RP are at a significantly greater risk of developing OAG than individuals without it.

Optical Coherence Tomography Angiography for the Evaluation of Retinal and Choroidal Vasculature in Retinitis Pigmentosa: A Monocentric Experience.

Purpose: We investigated the chorioretinal microvascular changes in patients with retinitis pigmentosa (RP) by optical coherence tomography angiography (OCTA). Methods: Twenty-six patients (52 eyes) affected by RP were compared with 19 healthy controls (38 eyes). OCTA 3 mm × 3 mm macular scans were performed in all subjects. We evaluated the vessel density (VD) of the superficial capillary plexus (VD SCP), deep capillary plexus (VD DCP), choriocapillaris (VD CC), and choroid (VD choroid). We also evaluated the foveal avascular zone (FAZ) area, and the correlation between clinical and OCTA parameters. We also measured central retinal thickness (CRT) and subfoveal choroidal thickness (CT). Results: RP patients compared to healthy controls showed significantly lower VD SCP values (27.56% ± 15.37 vs. 49.39% ± 1.55; p-value < 0.0001), lower VD DCP values (38.43% ± 15.23 vs. 3.34% ± 0.26; p-value < 0.0001), lower VD CC values (46.02% ± 1.293 vs. 50.63% ± 0.4274; p-value = 0.0040), and lower VD choroid values (38.48% ± 15.23 vs. 3.34% ± 0.26; p-value < 0.0001). Even the FAZ area was significantly lower in RP patients (0.45 mm2 ± 0.35 vs. 0.26 mm2 ± 0.13; p-value < 0.0001). The FAZ area was larger with increasing age, both in control (r = 0.42; p = 0.012) and RP group (r = 0.46; p-value = 0.009). In RP patients, there was a statistically significant correlation between best-corrected visual acuity and VD SCP (r = 0.24, p-value = 0.04) and VD DCP (r = 0.52; p-value = 0.0004) and between subfoveal choroidal thickness and VD SCP (r = 0.43, p-value < 0.001) and VD DCP (r = 0.35, p-value < 0.001). Conclusions: In our study, OCTA reported relevant vascular alterations in RP patients in comparison with the healthy controls, in agreement with the published literature. These abnormalities were associated with choroidal atrophy and related to visual acuity loss. OCTA provided clinically significant information and may represent a reliable tool for the management of RP patients.

Evaluation of vision-related quality of life in retinitis pigmentosa patients with low vision.

To investigate the effect of sociodemographic and clinical characteristics on vision-related quality of life (QoL) in retinitis pigmentosa (RP) patients with low vision. Retrospective. Thirty-three RP patients with low vision who had tunnel vision due to RP and 27 volunteers with healthy vision (controls) were included in the study. Visual loss was classified according to the International Classification of Diseases (ICD-10). The National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) was used to determine vision-related QoL. Static automated perimetry (Central 30-2 threshold program) was used for visual field testing, and the degree of the central visual field was calculated. Reading speed was calculated using the Minnesota Low-Vision Reading Acuity Chart (MNREAD) with best near correction. The mean total scores from the NEI VFQ-25 were 47.8 ± 15.8 in the RP group and 94.8 ± 4.3 in the control group (P < .001 for total and subscale scores). The mean total score and the social functioning and dependency scores were higher in the men than in the women (P = .016). The NEI VFQ-25 scores increased when reading speed was above 80 words per minute (wpm). Positive correlations were found between the degree of the central visual field and the mean total score and the general vision, near, and distance activities; social functioning; mental health; role difficulties; dependency; and color vision scores. The factors that affected the NEI-VFQ-25 score the most were male sex and degree of the central visual field in the RP group, whilst education level and the presence of systemic disease were the most effective factors in the controls. The only modifiable factor affecting vision-related QoL in patients with RP was reading speed; thus, QoL could improve if reading speed is increased in patients with RP.

Application of a Mapping Method in the Analysis of Electroretinogram in Patients with Retinitis Pigmentosa

ABSTRACT Purpose Retinitis pigmentosa (RP) is a group of degenerative retinal diseases characterized by mutations in genes affecting retinal pigment epithelium (RPE) function, as well as mutations directly involving photoreceptors. This paper aims to evaluate a nonlinear method to distinguish between the RP and normal eye based on the Electroretinogram (ERG) signal. Method ERG signal was recorded from 28 eyes of patients with the RP and 32 normal eyes. The ERG signal consists of four different stimuli, including two dark-adapted and two light-adapted stimuli. The time-domain analysis includes the amplitude and implicit time to consider the robustness of the nonlinear method. A parabolic mapping method was performed, and two criteria (Theta angle and density) extracted from the parabola were compared for both groups. Results The results showed that a-wave’s amplitude and implicit time significantly changed in the dark- and light-adapted stimuli. The amplitude of the b-wave showed significant changes in all stimuli. However, the implicit time of b-wave had a significant increase only in the dark-adapted 3.0 ERG. Both nonlinear criteria showed significant changes in the RP group for all the stimuli. The p-values of dark-adapted 3.0 (p = .0121), dark-adapted 10.0 (p = .0014), light-adapted 3.0 (p = .0119), and flicker 30 Hz (p = .0323) showed significant differences. Using the density criterion, the statistical test demonstrated a significant difference between the RP and healthy normal group in dark-adapted 3.0 (p = .0076), dark-adapted 10.0 (p = .0024), light-adapted 3.0 (p = .0021), and flicker 30 Hz (p = .0165). Conclusion The proposed features have made it possible to distinguish between healthy and RP eyes. This method might be helpful in early diagnosis.

New criteria for evaluation of electroretinogram in patients with retinitis pigmentosa.

Electroretinogram (ERG) plays an essential role in the diagnosis of retinal disease. Choosing appropriate methods could extract valuable information from ERG. In this study, a new criterion based on time-frequency domain analysis was proposed to investigate the retina in retinitis pigmentosa (RP) patients. The total number of 16 eyes from eight RP patients and 20 eyes from age-matched healthy subjects were assessed. The signals included photopic and scotopic ERGs. Continuous wavelet transform was applied to ERGs. Dominant frequencies were extracted, and the contours related to these dominant frequencies were selected. As a new criterion, the areas related to dominant frequency contours were considered a feature to differentiate the RP and normal groups. To better evaluate the proposed criterion results, the time-domain analysis characteristics of ERG were also considered. The results showed an increase in implicit time and reduced amplitude in RP patients (P < 0.05). A significant decrease of dominant frequencies and increasing their occurrence time were seen in ERG of RP patients. Also, in RP patients, the third dominant frequency was disappeared from the three main frequencies observed in photopic ERGs of normal subjects. The area criterion showed a significant decrease in RP groups (P < 0.05). RP can cause changes in the time and time-frequency components of the ERG. The area index could represent a new view of the characteristics of the ERG in the time-frequency domain. This criterion can help the ophthalmologist to have a better evaluation of retinal disease.

RETINAL AND CHOROIDAL BLOOD PERFUSION IN PATIENTS WITH BIETTI CRYSTALLINE DYSTROPHY.

To compare changes of chorioretinal blood perfusion between Bietti crystalline dystrophy (BCD) and typical retinitis pigmentosa and perform a staging and a longitudinal analysis of chorioretinal perfusion in BCD. Twenty-eight patients with BCD (56 eyes), 28 patients with typical retinitis pigmentosa (56 eyes), and 28 healthy subjects (56 eyes) were enrolled. Macular structural parameters and subfoveal choroidal thickness were measured using optical coherence tomography. Retinal vessel and perfusion densities were calculated using optical coherence tomography angiography. Choroidal blood perfusion was assessed through indocyanine green angiography. The results of the BCD group were compared with those of the retinitis pigmentosa and control groups and followed by a staging and a longitudinal analysis of BCD. Macular structural and perfusion parameters were decreased less in the BCD group than those in the retinitis pigmentosa group. Subfoveal choroidal thickness was significantly thinner in the BCD group, with a remarkable choroidal perfusion deficit using indocyanine green angiography. The staging analysis revealed damage of both retinal and choroidal perfusion in BCD; however, the longitudinal analysis showed the impairment of choroidal perfusion outweighed retinal. Both retinal and choroidal blood perfusion are impaired in BCD, but choroidal perfusion deficit caused by CYP4V2 mutations may play a more vital pathologic role.